1. Field of the Invention
The present invention relates generally to a camera, and more particularly to a camera that converts light into electric signals with an imaging device and displays a captured image on a displaying device such as a liquid crystal monitor.
2. Description of Related Art
Japanese patent provisional publication No. 4-324767 discloses a TV camera device that has an imaging device (CCD) with a shutter and an amplifier whose gain is variable. The TV camera device determines a brightness level of video signals on the field-by-field basis, and controls the shutter speed and the gain of the amplifier to obtain appropriate video signals.
Japanese patent provisional publication No. 6-54238 discloses a video camera that has a variable gain amplifier circuit for adjusting a brightness level of video signals to be outputted to a viewfinder. The video camera inputs the video signals obtained by an imaging system to a microcomputer, which determines the brightness level. The video camera controls the gain according to the brightness to obtain appropriate video signals.
However, in a method where a gain is controlled, if the gain is corrected beyond its effective level, the SN ratio is greatly lowered to make the image uneasy to see. For this reason, in the above methods, the correction of the video signals is finished before the SN ratio is lowered, and thus the image is not easy to see.
To address this problem, a digital camera with a displaying device such as a liquid crystal monitor has a switch for adjusting the brightness of the image on the displaying device. The user manually controls the brightness of the image with the switch when the subject is dark.